Chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is characterised by progressive airflow obstruction that is only partly reversible, inflammation in the airways, and systemic effects or comorbities. The main cause is smoking tobacco, but other factors have been identified. Several pathobiological processes interact on a complex background of genetic determinants, lung growth, and environmental stimuli. The disease is further aggravated by exacerbations, particularly in patients with severe disease, up to 78% of which are due to bacterial infections, viral infections, or both. Comorbidities include ischaemic heart disease, diabetes, and lung cancer. Bronchodilators constitute the mainstay of treatment: β(2) agonists and long-acting anticholinergic agents are frequently used (the former often with inhaled corticosteroids). Besides improving symptoms, these treatments are also thought to lead to some degree of disease modification. Future research should be directed towards the development of agents that notably affect the course of disease.

Antielastin B-cell and T-cell immunity in patients with chronic obstructive pulmonary disease

RATIONALE

Antielastin autoimmunity has been hypothesised to drive disease progression in chronic obstructive pulmonary disease (COPD). The proposed mechanism is currently disputed by conflicting data. The authors aimed to explore antibody responses against elastin in a large and extensively characterised COPD population and to assess elastin-specific peripheral T-cell reactivity in a representative subgroup.

METHODS

Antielastin antibodies were analysed with indirect ELISA on the plasma of 320 patients with COPD (Global Initiative for Chronic Obstructive Lung Disease 1-4) and 143 smoking controls. In a second group of 40 patients with COPD and smoking controls, T-cell responses against extracellular matrix (elastin, collagen I and collagen V) were determined with enzyme-linked immunosorbent spot (EliSpot) (interferon γ (IFNγ) and interleukin-2) on peripheral blood mononuclear cells and compared with the responses of 11 never-smoking controls.

RESULTS

Antielastin antibody titres were not elevated in patients with COPD compared with smoking controls and even decreased significantly with increasing severity of COPD (p<0.001). Lower antielastin antibody titres were also found in a subgroup of patients with CT-proven emphysema. Elastin-specific INFγ-mediated T helper 1 responses could not be revealed in smoking subjects with and without COPD. Collagen I-mediated T-cell responses were also absent, which contrasted with a significant increased anticollagen V response in the smoking controls and patients with COPD compared with the never smokers (p=0.008). Collagen V-mediated T-cell responses could not discriminate between patients with COPD and smoking controls.

CONCLUSION

A systemic immune response against elastin could not be identified in patients with COPD. By contrast, collagen V-mediated autoimmunity was increased in the subgroup of smokers and may potentially contribute to the pathogenesis of COPD.

Efficacy of tiotropium in COPD patients with FEV1 ≥ 60% participating in the UPLIFT® trial

GOLD stage II COPD encompasses patients with FEV₁ 50-80% predicted. A published trials review suggested that benefits of maintenance therapy are limited to patients with FEV₁ <60% predicted. We previously reported data demonstrating the efficacy of tiotropium in GOLD stage II disease in the 4-year UPLIFT® trial, and present here a further analysis of a sub-category of GOLD stage II patients with post-bronchodilator FEV1 ≥60% predicted from UPLIFT®. Outcomes included pre- and post-bronchodilator spirometry, exacerbations, SGRQ and mortality. Of the 5,992 UPLIFT® cohort, 1,210 (632 tiotropium, 578 control) had baseline post-bronchodilator FEV₁ ≥60% predicted (range 60-78%), mean age was 64 years, 70% were men, and mean SGRQ total score was 39.9 units. Mean annual rate of post-bronchodilator FEV₁ decline was 41 (tiotropium) and 49 (control) mL/year (P = 0.07); corresponding pre-bronchodilator values were 32 and 37 mL/year (P = 0.24). Morning pre-drug FEV₁ and FVC improvements for tiotropium versus control were 87-127 mL and 139-186 ml, respectively (P < 0.001, all time-points). SGRQ total score improvements (tiotropium-control) were 2.0-3.4 units (P < 0.05 for all); a higher percentage of patients had an improvement of ≥4 units with tiotropium (P <0.05). Tiotropium reduced risk for an exacerbation (HR [95% CI] = 0.83 [0.71, 0.96]) and mortality for the 4-year protocol-defined treatment period (HR [95% CI] = 0.66 [0.45, 0.96]). Tiotropium treatment provides clinical efficacy in patients with GOLD stage II disease with an FEV₁ ≥60% predicted, supporting current GOLD guidelines for COPD treatment. (ClinicalTrials.gov number NCT00144339).

Determinants of physical activity in daily life in candidates for lung transplantation

BACKGROUND

Participation in daily physical activity (PA) has never been objectively assessed in candidates for lung transplantation (LTx). The main research questions were: 1) How active are LTx-candidates in daily life? 2) What are determinants of activity behavior before LTX?

METHODS

Ninety-six candidates for LTx (diagnosis of COPD or interstitial lung disease; mean age 55 ± 7 years) underwent measurements of PA, pulmonary function, 6-min walking distance (6MWD), muscle force and health-status (SF-36 scale).

RESULTS

Patients were markedly inactive (5% of waking hours walking, 26% standing and 69% sedentary). Backward multiple regression identified 6MWD (expressed as % of predicted value; β = 73.0 steps, partial r(2) = 0.36, p = 0.00), a higher score on the energy/fatigue scale of the SF-36 (β = 28.6 steps, partial r(2) = 0.09, p = 0.00) and a higher expiratory muscle force (expressed as % of predicted value; β = 11.8 steps, partial r(2) = 0.05, p = 0.02) as determinants of daily steps. Minutes of mild to moderate (≥2 METs) activity were determined by 6MWD (expressed as % of predicted value; β = 2.14 min, partial r(2) = 0.30, p = 0.00), inspiratory muscle force (expressed as % of predicted value; β = 0.33 min, partial r(2) = 0.04, p = 0.05) and seasonal influences (spring/summer vs. autumn/winter: β = 18.95 min, partial r(2) = 0.04, p = 0.05). The overall fit of the models was r(2) = 0.50 and r(2) = 0.38, respectively.

CONCLUSIONS

The 6MWD was the main determinant of an inactive lifestyle in these patients. Respiratory muscle force, energy and fatigue and seasonal variations explained some additional variability in activity behavior. Patients should be encouraged to participate in interventions aimed at improving physical fitness and participation in daily physical activity before LTx.

Long-term nose-only cigarette smoke exposure induces emphysema and mild skeletal muscle dysfunction in mice

Mouse models of chronic obstructive pulmonary disease (COPD) focus on airway inflammation and lung histology, but their use has been hampered by the lack of pulmonary function data in their assessment. Systemic effects such as muscle dysfunction are also poorly modeled in emphysematous mice. We aimed to develop a cigarette-smoke-induced emphysema mouse model in which serial lung function and muscular dysfunction could be assessed, allowing the disease to be monitored more appropriately. C57Bl6 mice were nose-only exposed to cigarette smoke or filtered air for 3–6 months. Lung function tests were repeated in the same mice after 3 and 6 months of cigarette smoke or air exposure and compared with lung histological changes. Contractile properties of skeletal muscles and muscle histology were also determined at similar time points in separate groups of mice. Serial lung function measurements documented hyperinflation after 3 and 6 months of cigarette smoke exposure, with a significant 31–37% increase in total lung capacity (TLC) and a significant 26–35% increase in compliance (Cchord) when compared with animals exposed to filtered air only (P<0.001 after 3 and after 6 months). These functional changes preceded the changes in mean linear intercept, which became only significant after 6 months of cigarette smoke exposure and which correlated very well with TLC (r=0.74, P=0.004) and Cchord (r=0.79, P=0.001). After 6 months of cigarette smoke exposure, a significant fiber-type shift from IIa to IIx/b was also observed in the soleus muscle (P<0.05), whereas a 20% reduction of force was present at high stimulation frequencies (80 Hz; P=0.09). The extensor digitorum longus (EDL) muscle was not affected by cigarette smoke exposure. These serial pulmonary function variables are sensitive outcomes to detect emphysema progression in a nose-only cigarette-smoke-exposed animal model of COPD. In this model, muscular changes became apparent only after 6 months, particularly in muscles with a mixed fiber-type composition.

Accuracy of office spirometry performed by trained primary-care physicians using the MIR Spirobank hand-held spirometer

BACKGROUND

With the availability of compact, portable, effective microspirometers, pulmonary function tests no longer need to be performed only in specialized laboratories. However, the perception persists that small flow-sensing devices are less accurate than volume-sensing spirometers.

OBJECTIVES

To study the accuracy of spirometry performed with the MIR Spirobank® and to investigate how accurately trained primary-care physicians can perform spirometry using a portable electronic spirometer.

METHODS

Patients with suspected occupational asthma were submitted to specific bronchial challenge tests in the pulmonary function laboratory according to published recommendations. Serial measurements were performed with the Jaeger MasterScope device (reference standard) or the Spirobank device. Data were generated from 908 parallel measurements on 34 patients. Furthermore, 16 patients with documented moderate to severe COPD were examined in a carousel set-up by four trained physicians who each used his/her own Spirobank device coupled to a laptop computer.

RESULTS

The Spirobank spirometer performed very well compared with the Jaeger MasterScope in a laboratory environment, displaying an underestimation of the forced expiratory volume in 1 s (FEV(1)) and FEV(1)/forced vital capacity (FVC) of 2-5%. High correlations were found for the pulmonary function parameters. The highest correlation was for FEV(1) (r(2) = 0.949) and the lowest for the maximum expiratory flow at 25% of FVC (MEF(25)) (r(2) = 0.864). Only 2% of the observed variation in the measurement results could be explained by the type of device.

CONCLUSIONS

The Spirobank device seems to be appropriate for research purposes if the standardized protocol is used correctly and the acceptability criteria are respected.

High doses of vitamin D to reduce exacerbations in chronic obstructive pulmonary disease: a randomized trial

BACKGROUND

Low serum 25-hydroxyvitamin D (25-[OH]D) levels have been associated with lower FEV(1), impaired immunologic control, and increased airway inflammation. Because many patients with chronic obstructive pulmonary disease (COPD) have vitamin D deficiency, effects of vitamin D supplementation may extend beyond preventing osteoporosis.

OBJECTIVE

To explore whether supplementation with high doses of vitamin D could reduce the incidence of COPD exacerbations.

DESIGN

Randomized, single-center, double-blind, placebo-controlled trial. (ClinicalTrials.gov registration number: NCT00666367)

SETTING

University Hospitals Leuven, Leuven, Belgium.

PATIENTS

182 patients with moderate to very severe COPD and a history of recent exacerbations.

INTERVENTION

100,000 IU of vitamin D supplementation or placebo every 4 weeks for 1 year.

MEASUREMENTS

The primary outcome was time to first exacerbation. Secondary outcomes were exacerbation rate, time to first hospitalization, time to second exacerbation, FEV(1), quality of life, and death.

RESULTS

Mean serum 25-(OH)D levels increased significantly in the vitamin D group compared with the placebo group (mean between-group difference, 30 ng/mL [95% CI, 27 to 33 ng/mL]; P < 0.001). The median time to first exacerbation did not significantly differ between the groups (hazard ratio, 1.1 [CI, 0.82 to 1.56]; P = 0.41), nor did exacerbation rates, FEV(1), hospitalization, quality of life, and death. However, a post hoc analysis in 30 participants with severe vitamin D deficiency (serum 25-[OH]D levels <10 ng/mL) at baseline showed a significant reduction in exacerbations in the vitamin D group (rate ratio, 0.57 [CI, 0.33 to 0.98]; P = 0.042).

LIMITATION

This was a single-center study with a small sample size.

CONCLUSION

High-dose vitamin D supplementation in a sample of patients with COPD did not reduce the incidence of exacerbations. In participants with severe vitamin D deficiency at baseline, supplementation may reduce exacerbations.

PRIMARY FUNDING SOURCE

Applied Biomedical Research Program, Agency for Innovation by Science and Technology (IWT-TBM).

Efficacy of tiotropium in COPD patients from Asia: a subgroup analysis from the UPLIFT trial

BACKGROUND AND OBJECTIVE

Studies in respiratory diseases other than chronic obstructive pulmonary disease suggest potentially differing responses to medications among patients from different regions. We report a subgroup analysis of patients recruited to Asian centres from a previously reported 4-year COPD trial.

METHODS

Subgroup analysis from a randomized, double-blinded, placebo-controlled trial of tiotropium 18 µg daily in COPD. Primary end-point was rate of decline in FEV(1) . Secondary end-points included spirometry at individual time points, health-related quality of life (St George's Respiratory Questionnaire), exacerbations and mortality.

RESULTS

Of 5992 patients, 362 were from Asian centres (100 from Japan). Mean age 66 years, 95% men, 13% current smokers, BMI: 21 kg/m(2) ; post-bronchodilator FEV(1) : 44% predicted; St George's Respiratory Questionnaire total score: 44 units. No treatment effect was observed for rate of decline in FEV(1) although annual decline was less in Asian patients. Morning pre-bronchodilator FEV(1) and forced vital capacity improved in Asian patients (P < 0.05). Tiotropium reduced number of exacerbations (rate ratio (95% confidence interval (CI)): 0.73 (0.57-0.94)). Hazard ratios (95%CI) for exacerbations and hospitalized exacerbations (tiotropium/control) were 0.81 (0.62-1.05) and 0.85 (0.61-1.19), respectively. St George's Respiratory Questionnaire total score improved by 1.5-6.1 units (P < 0.05 for months 18, 24, 30 and 36) with tiotropium. Fatal events occurred in 34 tiotropium (18.5%) and 42 control (23.6%) patients.

CONCLUSIONS

In COPD patients from Asia, tiotropium improves lung function, improves health-related quality of life and reduces exacerbations over 4 years of treatment.

Effectiveness of exercise training in patients with COPD: the role of muscle fatigue

The improvement in exercise performance in response to exercise training varies greatly from one patient with chronic obstructive pulmonary disease to another. It is possible that in a portion of patients the muscle stimulus applied during exercise training is insufficient to elicit training effects. We investigated whether patients presenting quadriceps contractile fatigue after training have more favourable effects of a rehabilitation programme. 46 patients followed a 3-month high-intensity exercise training programme. Exercise capacity, quadriceps force and quality of life were measured before and after the programme. Exercise training-induced quadriceps contractile fatigue was assessed after 1 month of rehabilitation with magnetic stimulation. A fall in quadriceps force of ≥15%, 15 min after training was considered as significant fatigue. 29 (63%) out of 46 patients developed significant fatigue. Patients with fatigue had a higher increase in 6-min walk distance (median (interquartile range) 57 (47-103) m versus 17 (-7-46) m; p=0.0023) and Chronic Respiratory Disease Questionnaire score (mean±sd 22±12 points versus 14±12 points; p=0.028) after the training programme compared with patients without fatigue. Improvements in quadriceps force and maximal exercise capacity were similar in both subgroups. Patients who develop quadriceps contractile fatigue during exercise training show greater training effects in terms of functional exercise capacity and health-related quality of life.

Differential diagnosis in a primary care population with presumed airway obstruction: a real-life study

BACKGROUND

Asthma and chronic obstructive pulmonary disease (COPD) have major symptoms in common. However, the mode of the underlying chronic airway inflammation is different. There is still no single diagnostic test that can be considered a gold standard to distinguish asthma from COPD.

OBJECTIVES

To determine the diagnostic accuracy for asthma and COPD of a series of diagnostic steps in a population older than 40 years with probable obstructive airway disease (OAD) in primary care.

METHODS

In this prospective cohort study, patients without a certain diagnosis underwent a work-up, including office spirometry by their general practitioner (GP). They were then referred to a pulmonologist, and they had control visits with their GP. The diagnostic gain of subsequent steps was calculated for 2 endpoints, namely the specialist's opinion and the GP's final opinion.

RESULTS

Up to 60% of the patients failed to consult with the pulmonologist. For this subgroup, the office spirometry induced significantly more diagnostic congruency than any other diagnostic step. The specialists rejected 44.5% of the diagnoses made by the GPs, including spirometry. High values of diagnostic gain were found after the office spirometry and after the specialist's advice. Up to 25% of the population taking bronchodilators were judged not to suffer from OAD.

CONCLUSIONS

Office spirometry added significantly more to the diagnostic certainty of the GPs than questionnaires, history and clinical examination. A pulmonologist's advice contributed more to diagnostic certainty than any other diagnostic step. Nevertheless, 26% of the diagnoses made by the chest physicians were reconsidered by the GPs.

Adverse health consequences in COPD patients with rapid decline in FEV1--evidence from the UPLIFT trial

BACKGROUND

The rate of decline in forced expiratory volume in 1 second (FEV1) is representative of the natural history of COPD. Sparse information exists regarding the associations between the magnitude of annualised loss of FEV1 with other endpoints.

METHODS

Retrospective analysis of UPLIFT® trial (four-year, randomized, double-blind, placebo-controlled trial of tiotropium 18 μg daily in chronic obstructive pulmonary disease [COPD], n = 5993). Decline of FEV1 was analysed with random co-efficient regression. Patients were categorised according to quartiles based on the rate of decline (RoD) in post-bronchodilator FEV1. The St George's Respiratory Questionnaire (SGRQ) total score, exacerbations and mortality were assessed within each quartile.

RESULTS

Mean (standard error [SE]) post-bronchodilator FEV1 increased in the first quartile (Q1) by 37 (1) mL/year. The other quartiles showed annualised declines in FEV1 (mL/year) as follows: Q2 = 24 (1), Q3 = 59 (1) and Q4 = 125 (2). Age, gender, respiratory medication use at baseline and SGRQ did not distinguish groups. The patient subgroup with the largest RoD had less severe lung disease at baseline and contained a higher proportion of current smokers. The percentage of patients with ≥ 1 exacerbation showed a minimal difference from the lowest to the largest RoD, but exacerbation rates increased with increasing RoD. The highest proportion of patients with ≥ 1 hospitalised exacerbation was in Q4 (Q1 = 19.5% [tiotropium], 26% [control]; Q4 = 33.8% [tiotropium] and 33.1% [control]). Time to first exacerbation and hospitalised exacerbation was shorter with increasing RoD. Rate of decline in SGRQ increased in direct proportion to each quartile. The group with the largest RoD had the highest mortality.

CONCLUSION

Patients can be grouped into different RoD quartiles with the observation of different clinical outcomes indicating that specific (or more aggressive) approaches to management may be needed.

TRIAL REGISTRATION

ClinicalTrials.gov number, NCT00144339.

Risk of nonlower respiratory serious adverse events following COPD exacerbations in the 4-year UPLIFT® trial

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) exacerbations are associated with systemic consequences. Data from a 4-year trial (Understanding Potential Long-term Impacts on Function with Tiotropium [UPLIFT(®)], n = 5,992) were used to determine risk for nonlower respiratory serious adverse events (NRSAEs) following an exacerbation.

METHODS

Patients with ≥ 1 exacerbation were analyzed. NRSAE incidence rates (incidence rate [IR], per 100 patient-years) were calculated for the 30 and 180 days before and after the first exacerbation. NRSAEs were classified by diagnostic terms and organ classes. Maentel-Haenszel rate ratios (RR) (pre- and postexacerbation onset) along with 95% confidence intervals (CI) were computed.

RESULTS

A total of 3,960 patients had an exacerbation. The mean age was 65 years, forced expiratory volume in 1 s (FEV(1)) was 38% predicted, and 74% were men. For all NRSAEs, the IRs 30 days before and after an exacerbation were 20.2 and 65.2 with RR (95% CI) = 3.22 (2.40-4.33). The IRs for the 180-day periods were 13.2 and 31.0 with RR (95% CI) = 2.36 (1.93-2.87). The most common NRSAEs by organ class for both time periods were cardiac, respiratory system (other), and gastrointestinal. All NRSAEs as well as cardiac events were more common after the first exacerbation, irrespective of whether the patient had cardiac disease at baseline.

CONCLUSIONS

The findings confirm that, after exacerbations, serious adverse events in other organ systems are more frequent, particularly those that are cardiac in nature.

Impact of inspiratory muscle training in patients with COPD: what is the evidence?

A meta-analysis including 32 randomised controlled trials on the effects of inspiratory muscle training (IMT) in chronic obstructive pulmonary disease (COPD) patients was performed. Overall and subgroup analyses with respect to training modality (strength or endurance training, added to general exercise training) and patient characteristics were performed. Significant improvements were found in maximal inspiratory muscle strength (P(I,max); +13 cmH₂O), endurance time (+261 s), 6- or 12-min walking distance (+32 and +85 m respectively) and quality of life (+3.8 units). Dyspnoea was significantly reduced (Borg score -0.9 point; Transitional Dyspnoea Index +2.8 units). Endurance exercise capacity tended to improve, while no effects on maximal exercise capacity were found. Respiratory muscle endurance training revealed no significant effect on P(I,max), functional exercise capacity and dyspnoea. IMT added to a general exercise programme improved P(I,max) significantly, while functional exercise capacity tended to increase in patients with inspiratory muscle weakness (P(I,max) <60 cmH₂O). IMT improves inspiratory muscle strength and endurance, functional exercise capacity, dyspnoea and quality of life. Inspiratory muscle endurance training was shown to be less effective than respiratory muscle strength training. In patients with inspiratory muscle weakness, the addition of IMT to a general exercise training program improved P(I,max) and tended to improve exercise performance.